IstoPore Seminar – by Laura Spitzmüller

Abstract

Accurate understanding of reservoir geometry and flow paths is crucial for successful geothermal operations. Conventional hydraulic testing and tracer tests often yield inconclusive or limited data due to the complex reservoir conditions (e.g., multi-well systems, complex geometry, fracture networks, etc.) A novel type of tracer technique, nano-particle-based tracers, has emerged to overcome the limitations of conventional molecular tracers. Nano-particle tracers offer tunable properties and modular structure, providing significant advantages over molecular tracers. Despite these advances, interactions between particles, fluids, and rock minerals in complex geothermal environments are the subject of ongoing research. For example, embedding or attaching tracing features (e.g., fluorescent molecules, DNA) to a silica matrix can shield the tracing function from environmental influences such as pH, salinity, or temperature. While silica’s (hydro)thermal stability is low, the herein presented surface modification strategy protects the silica matrix effectively. Moreover, the adaptability of the ζ-potential of nano-particles through surface modifications is another benefit, minimizing sorption and retention, as presented in this study.